Ubuntu: Automatically Disable Touchpad when External Mouse Connected

Introduction:

If you’re like me, you hate using your touchpad when you could be using an external mouse. If you’re like me you also have a habit of disabling your touchpad when using a mouse, and forgetting to re-enable it until after you unplug your mouse. If you’re like me, this tutorial is exactly what you need.

What you need to get started:

You will need to make sure that you have xinput and halevt installed. You almost certainly already have xinput, but the following command will make sure you have what you need:

sudo aptitude install xinput halevt

I also recommend that you create a folder for scripts (if you haven’t already), and add it to your $PATH. I created a “bin” folder in my home directory for this. Create the folder with:

mkdir ~/bin

and add it to your path by issuing the following commands:

echo "PATH=\$PATH:~/bin" >> ~/.bashrc
echo "export PATH" >> ~/.bashrc

Configure the script:

First we need to create and configure the script which will actually toggle the touchpad:

cd ~/bin
touch toggleTouchpad
gedit toggleTouchpad

The script should now be open in gedit (feel free to replace gedit with your favorite text editor). Paste the following into the script:

If your touchpad has the word “TouchPad” (case sensitive) in it, the script is ready to go. If it doesn’t, edit the variable “touchpadString” in the script to match your touchpad… but remember everything is case sensitive. For now, your script is configured. Next step is testing.

Test the script:

Make sure your touchpad is working, and then open a new terminal window. We are going to do four tests. Before and after each test, try your touchpad.

Test 1:

toggleTouchpad

Did your touchpad stop working? Good!

Test 2:

toggleTouchpad

Did your touchpad start working again? Good!

Test 3:

toggleTouchpad off

Wait at least one second…
Did your touchpad stop working? Good!

Test 4:

toggleTouchpad on

Wait at least one second…
Did your touchpad start working again? Good!

Making the magic happen automatically:

We’re almost there! Now we need to set the script to run automatically when your mouse is plugged in. Making sure your mouse is unplugged, run the following command:

halevt -i >>~/connectedDevices.txt

While the command is running, plug in your mouse, and then unplug it. Now press Ctrl +c to kill the process. Open ~/connectedDevices.txt, and you should see something that looks like:

All of those devices are your mouse. Since each of those events will trigger every time you plug in your mouse, we only need to handle one of them. Pick one that ends in seemingly random numbers, and copy and paste everything after the “:” into a text file. We will be using it in a moment. Now, let’s create our halevt config file:

Test the Magic:

Now, connect your mouse. If all is going well, about ~1.5 seconds after you plug in your mouse your touchpad should stop working. Now, disconnect your mouse. Your touchpad should start working again.

Making it permanent:

If all went well in the tests, you will want to make this happen automatically forever. Go to “System->Preferences->Startup Applications”, and add a new startup program. Name it something you will remember, and for the command put “halevt -c ~/.halevt.xml”. You’re done!!

Brendon Dugan

I can’t seem to get the last piece of the puzzle working. The toggle tests work fine. I’ve substituted my device /org/freedesktop/Hal/devices/usb_device_46d_c52b_noserial but the halevt script doesn’t seem to be detecting the change.